Display device, method for manufacturing display device, display module, and electronic device

Abstract

A highly reliable display device with high display quality is provided. The display device includes a first light-emitting element, a second light-emitting element provided to be adjacent to the first light-emitting element, a first protective layer, a second protective layer, and an insulating layer. The first light-emitting element includes a first pixel electrode, a first EL layer, and a common electrode, and the second light-emitting element includes a second pixel electrode, a second EL layer, and the common electrode. The first EL layer is provided over the first pixel electrode, and the second EL layer is provided over the second pixel electrode. The first protective layer includes a region in contact with the side surface of the first EL layer, and the second protective layer includes a region in contact with the side surface of the second EL layer. The insulating layer is provided between the first protective layer and the second protective layer. The common electrode is provided over the first EL layer, over the second EL layer, over the first protective layer, over the second protective layer, and over the insulating layer.

1 . A display device comprising:
 a first light-emitting element;   a second light-emitting element positioned to be adjacent to the first light-emitting element;   a first protective layer;   a second protective layer; and   an insulating layer,   wherein the first light-emitting element comprises a first pixel electrode, a first EL layer, and a common electrode,   wherein the second light-emitting element comprises a second pixel electrode, a second EL layer, and the common electrode,   wherein the first EL layer is provided over the first pixel electrode,   wherein the second EL layer is provided over the second pixel electrode,   wherein the first protective layer comprises a region in contact with a side surface of the first EL layer,   wherein the second protective layer comprises a region in contact with a side surface of the second EL layer,   wherein the insulating layer is provided between the first protective layer and the second protective layer, and   wherein the common electrode is provided over the first EL layer, over the second EL layer, over the first protective layer, over the second protective layer, and over the insulating layer.   
     
     
         2 . The display device according to  claim 1 ,
 wherein the insulating layer contains an organic material.   
     
     
         3 . The display device according to  claim 2 ,
 wherein the insulating layer contains a photosensitive resin.   
     
     
         4 . The display device according to  claim 1 ,
 wherein the first protective layer and the second protective layer each contain an inorganic material.   
     
     
         5 . The display device according to  claim 1 ,
 wherein a common layer is provided between the common electrode and the first EL layer, the second EL layer, the first protective layer, the second protective layer, and the insulating layer, and   wherein the common layer comprises at least one of a hole-injection layer, a hole-transport layer, a hole-blocking layer, an electron-blocking layer, an electron-transport layer, or an electron-injection layer in the first light-emitting element and the second light-emitting element.   
     
     
         6 . The display device according to  claim 1 , comprising a region where a distance between the side surface of the first EL layer and the side surface of the second EL layer is less than or equal to 1 μm. 
     
     
         7 . The display device according to  claim 6 , comprising a region where the distance between the side surface of the first EL layer and the side surface of the second EL layer is less than or equal to 100 nm. 
     
     
         8 . The display device according to  claim 1 ,
 wherein the first light-emitting element comprises a third protective layer, wherein the second light-emitting element comprises a fourth protective layer,   wherein the third protective layer comprises a region in contact with a side surface of the first pixel electrode,   wherein the fourth protective layer comprises a region in contact with a side surface of the second pixel electrode, and   wherein the insulating layer is provided between the third protective layer and the fourth protective layer.   
     
     
         9 . The display device according to  claim 8 ,
 wherein the third protective layer and the fourth protective layer each contain an inorganic material.   
     
     
         10 . A display module comprising:
 the display device according to  claim 1 ; and   at least one of a connector and an integrated circuit.   
     
     
         11 . An electronic device comprising:
 the display module according to  claim 10 ; and   at least one of a housing, a battery, a camera, a speaker, and a microphone.   
     
     
         12 . A method for manufacturing a display device, comprising:
 forming a first pixel electrode and a second pixel electrode over an insulating surface;   forming a first EL film and a first sacrificial film in this order over the first pixel electrode and over the second pixel electrode;   processing the first sacrificial film and the first EL film to form a first sacrificial layer and a first EL layer each of which comprises a region overlapping with the first pixel electrode;   forming a first protective film covering at least a side surface of the first EL layer and a side surface and a top surface of the first sacrificial layer;   processing the first protective film to form a first protective layer comprising a region in contact with at least the side surface of the first EL layer;   forming a second EL film and a second sacrificial film in this order over the first sacrificial layer and over the second pixel electrode;   processing the second sacrificial film and the second EL film to form a second sacrificial layer and a second EL layer each of which comprises a region overlapping with the second pixel electrode;   forming a second protective film covering at least a side surface of the second EL layer and a side surface and a top surface of the second sacrificial layer;   processing the second protective film to form a second protective layer comprising a region in contact with at least the side surface of the second EL layer;   forming an insulating film covering at least the top surface of the first sacrificial layer, the top surface of the second sacrificial layer, a side surface of the first protective layer, and a side surface of the second protective layer;   processing the insulating film to form an insulating layer between the first protective layer and the second protective layer;   removing the first sacrificial layer and the second sacrificial layer; and   forming a common electrode over the first EL layer, over the second EL layer, over the first protective layer, over the second protective layer, and over the insulating layer.   
     
     
         13 . The method for manufacturing a display device, according to  claim 12 ,
 wherein the first protective film and the second protective film are formed by an ALD method, a sputtering method, or a CVD method, and   wherein the insulating film is formed by a spin coating method, a spraying method, a screen printing method, or a painting method.   
     
     
         14 . The method for manufacturing a display device, according to  claim 12 ,
 wherein before the common electrode is formed, at least one of a hole-injection layer, a hole-transport layer, a hole-blocking layer, an electron-blocking layer, an electron-transport layer, or an electron-injection layer is formed as a common layer over the first EL layer, over the second EL layer, over the first protective layer, over the second protective layer, and over the insulating layer.   
     
     
         15 . The method for manufacturing a display device, according to  claim 12 ,
 wherein the second EL film is processed to comprise a region where a distance between the side surface of the first EL layer and the side surface of the second EL layer is less than or equal to 1 μm.   
     
     
         16 . The method for manufacturing a display device, according to  claim 15 ,
 wherein the second EL film is processed to comprise a region where the distance between the side surface of the first EL layer and the side surface of the second EL layer is less than or equal to 100 nm.   
     
     
         17 . The method for manufacturing a display device, according to  claim 12 ,
 wherein the first protective film is processed to form a third protective layer comprising a region in contact with at least a side surface of the first pixel electrode in addition to the first protective layer comprising the region in contact with at least the side surface of the first EL layer,   wherein the second protective film is processed to form a fourth protective layer comprising a region in contact with at least a side surface of the second pixel electrode in addition to the second protective layer comprising the region in contact with at least the side surface of the second EL layer, and   wherein the insulating film is processed to form the insulating layer comprising a region in contact with a side surface of the third protective layer and a side surface of the fourth protective layer, in addition to the side surface of the first protective layer and the side surface of the second protective layer.